I know that you need to get overall 90% from all A2 papers. Does the percentage kinda vary from that year boundaries? For example, if everyone in UK does very bad in the maths A2 papers and the boundaries are very low, like 60% of actual paper marks is A, do I still need 90% of all marks to get A*?

You don't need 90% to get an A*, but instead 90 UMS. UMS for each mark varies year by year, as papers vary in difficulty, but I doubt that 90 UMS would be anywhere near 60%, maybe 75-80% on a VERY hard paper

you need 90% in UMS on average across A2 units with 80% average UMS across the whole A-level. It is always 90% UMS, however for each paper the marks you need for 90% UMS varies, if its a hard paper you may need only 70% of the marks for example to get 90% UMS.

(Original post by Neymar99)
You don't need 90% to get an A*, but instead 90 UMS. UMS for each mark varies year by year, as papers vary in difficulty, but I doubt that 90 UMS would be anywhere near 60%, maybe 75-80% on a VERY hard paper

no you need 90% in UMS, not 90 UMS as some papers are worth 60 UMS some are worth 120 UMS etc